The present invention relates to a rotary electric machine mounted within a passenger car, truck or other vehicles, in which heat-generating bodies are cooled by circulation of cooling medium.
In JP-A-59-209053, it is proposed to provide, in a rotary electric machine, a flexible damping member between a stator core and a housing to restrict resonance noise due to vibration of the stator core. However, because the damping member is disposed proximate to the stator core, the damping member is heated due to an excessive current loss of the stator core or the like. As a result, the damping member is deteriorated. Further, the stator core is likely to be moved by magnetic force of the rotor due to decrease in holding power of the stator core.
In JP-B2-5-16261 (U.S. Pat. No. 4,818,906), in a rotary electric machine, a coolant passage for flowing engine coolant is formed in a housing to cool electric components such as an armature coil and a commutating device. However, when the coolant passage is formed in the housing, the housing is necessarily decreased in thickness to maintain a size of an external form or an axial length of the rotary electric machine. Accordingly, rigidity of the housing is lessened, and as a result, magnetic noise is likely to increase.
The present invention is made in view of the above problems, and it is an object of the present invention to provide a rotary electric machine mounted on a vehicle, in which a temperature rise of a damping member is suppressed and magnetic noise is decreased.
According to the present invention, a stator coolant passage means including a damping member and a stator coolant tube is provided between a housing and a stator core to surround the outer periphery of the stator core. Therefore, the stator core is cooled by coolant flowing in the stator coolant tube so that the temperature rise of the damping member is suppressed. Accordingly, the damping member is restricted from deteriorating due to high temperature and maintains flexibility so that a stator is prevented from moving. Further, vibration of the stator is suppressed, and as a result, magnetic noise is decreased.
Moreover, an additional coolant tube is provided near other heat-generating bodies. In this case, the coolant flows in the stator coolant tube prior to the second coolant tube. Therefore, the coolant flowing in the stator coolant tube is not affected thermally by the coolant flowing in the additional coolant tube. Accordingly, the temperature rise of the damping member is effectively restricted.